o.k., we've solved the recent problem...
history: bought the used RV back in June, fridge and freezer worked perfectly all that time since
recent: fridge lost cooling, freezer seemed to be working just fine
SOLUTION: I realized that recently while 'winterizing' much of the RV, and having put insulation batts behind each outside compartment door, I had also had the 'brilliant' idea of also putting insulation batts behind the fridge's outside vent cover.
I now realize that this is a mistake, as RV fridge's need air flow...
when we removed the insulation yesterday, the fridge today is suddenly COOLING just as it should be....solved.